Coated abrasive article and method of making the same

ABSTRACT

A coated abrasive article comprises a backing having first and second opposed major surfaces, a make layer disposed on at least a portion of the first major surface and bonding abrasive particles to the backing, a size layer overlaid on at least a portion of the make layer and the abrasive particles, and an optional supersize layer. At least one of the size layer or the optional supersize layer comprises an at least partially cured resole phenolic resin and an organic polymeric rheology modifier, and wherein the amount of the at least partially cured resole phenolic resin comprises from 75 to 99.99 weight percent of the combined weight of the at least partially cured resole phenolic resin and the organic polymeric rheology modifier. A method of making the coated abrasive article is also disclosed.

TECHNICAL FIELD

The present disclosure relates to abrasive articles including a phenolicbinder material and abrasive particles, and methods of making the same.

BACKGROUND

Abrasive articles generally comprise abrasive particles (also known as“grains”) retained within a binder. During manufacture of various typesof abrasive articles, the abrasive particles are deposited on a bindermaterial precursor in an oriented manner (e.g., by electrostatic coatingor by some mechanical placement technique). Typically, the mostdesirable orientation of the abrasive particles is substantiallyperpendicular to the surface of the backing.

In the case of certain coated abrasive articles (e.g., grinding discs),the backing is a relatively dense planar substrate (e.g., vulcanizedfiber or a woven or knit fabric, optionally treated with a saturant toincrease durability). A make layer precursor (or make coat) containing afirst binder material precursor is applied to the backing, and then theabrasive particles are partially embedded into the make layer precursor.Frequently, the abrasive particles are embedded in the make layerprecursor with a degree of orientation; e.g., by electrostatic coatingor by a mechanical placement technique. The make layer precursor is thenat least partially cured in order to retain the abrasive particles whena size layer precursor (or size coat) containing a second bindermaterial precursor is overlaid on the at least partially cured makelayer precursor and abrasive particles. Next, the size layer precursor,and the make layer precursor if not sufficiently cured, are cured toform the coated abrasive article. In some instances, a supersize layeroverlays the size layer.

For thermally cured size layer precursors, the coated abrasive productis often manufactured as a continuous web that is dried and cured infestoon ovens, where the web is draped over hanger bars that progressthrough the oven.

SUMMARY

Flow of the size layer precursor and/or supersize layer due to gravitycan be a problem during curing in a festoon oven, especially if theabrasive particles are aligned such that flow is not impeded by theabrasive particles. However, the recent trend toward precise placementand/or orientation of the abrasive particles has increased the need fora solution to the gravity flow problem discussed above.

The present disclosure overcomes this problem by using a resolephenolic-based curable composition (typically thixotropic) suitable foruse in manufacture of an abrasive article. The curable compositioncomprises a liquid phenolic resin and an organic polymeric rheologymodifier comprising an alkali-swellable/soluble polymer. These organicpolymeric rheology modifiers are presently discovered to provide bettercontrol of size layer precursor flow than the techniques previouslyused.

Organic polymeric rheology modifiers are known to give pseudoplasticflow characteristics.

Particularly, Alkali-Swellable/soluble Emulsion (ASE) polymers,Hydrophobically-modified Alkali-Swellable/soluble Emulsion (HASE)polymers, and Hydrophobically-modified Ethoxylated URethane (HEUR)polymers have been used in aqueous compositions for latex paints,personal care products, and drilling muds. As used herein, the term“Alkali-Swellable/soluble Emulsion (ASE) polymers” expressly excludesHydrophobically-modified Alkali-Swellable/soluble Emulsion (HASE)polymers.

In a first aspect, the present disclosure provides a method of making acoated abrasive article comprising:

providing a backing having first and second opposed major surfaces,wherein a make layer is disposed on at least a portion of the firstmajor surface and bonds abrasive particles to the backing;

coating a size layer precursor over at least a portion of the make layerand the abrasive particles, wherein the size layer precursor comprises aresole phenolic resin and. an organic polymeric rheology modifier,wherein the organic polymeric rheology modifier comprises analkali-swellable/soluble polymer, and, on a solids basis, and whereinthe amount of the resole phenolic resin comprises from 75 to 99.99weight percent of the combined weight of the resole phenolic resin andthe organic polymeric rheology modifier; and at least partially curingthe size layer precursor to provide a size layer; and optionally coatingan optional supersize layer precursor over at least a portion of thesize layer and at least partially curing the optional supersize layerprecursor to provide an optional supersize layer, wherein at least oneof the size layer precursor or the optional supersize layer precursorcomprises a resole phenolic resin and an organic polymeric rheologymodifier, wherein the organic polymeric rheology modifier comprises analkali-swellable/soluble polymer, and, on a solids basis, and whereinthe amount of the resole phenolic resin comprises from 75 to 99.99weight percent of the combined weight of the resole phenolic resin andthe organic polymeric rheology modifier.

In a second aspect, the present disclosure provides a coated abrasivearticle comprising:

a backing having first and second opposed major surfaces, a make layerdisposed on at least a portion of the first major surface and bondingabrasive particles to the backing;

a size layer overlaid on at least a portion of the make layer and theabrasive particles; and

an optional supersize layer, wherein at least one of the size layer orthe optional supersize layer comprises an at least partially curedresole phenolic resin and an organic polymeric rheology modifier, andwherein the amount of the at least partially cured resole phenolic resincomprises from 75 to 99.99 weight percent of the combined weight of theat least partially cured resole phenolic resin and the organic polymericrheology modifier. As used herein:

“alkali-swellable” means at least partially swellable in an aqueoussolution of a water-soluble base having a pH of greater than 7;

“alkali-swellable/soluble” means at least one of alkali-swellable oralkali-soluble (i e, alkali-swellable and/or alkali-soluble), and“polymer” refers to an organic polymer unless otherwise clearlyindicated.

Features and advantages of the present disclosure will be furtherunderstood upon consideration of the detailed description as well as theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional side view of an exemplary coatedabrasive article 100 according to the present disclosure.

FIG. 2 is a schematic perspective view of exemplary precisely-shapedabrasive particle 200. It should, be understood that numerous othermodifications and embodiments can be devised by those skilled in theart, which fall within the scope and spirit of the principles of thedisclosure. The figures may not be drawn to scale.

DETAILED DESCRIPTION

An exemplary embodiment of a coated abrasive article according to thepresent disclosure is depicted in FIG. 1 . Referring now to FIG. 1 ,coated abrasive article 100 has backing 120 and abrasive layer 130.Abrasive layer 130 includes abrasive particles 140 secured to majorsurface 170 of backing 120 by make layer 150 and size layer 160.Optional supersize layer ISO overlays size layer 160.

Coated abrasive articles according to the present disclosure may includeadditional layers such as, for example, a backing antistatic treatmentlayer and/or an attachment layer may also be included, if desired.

Useful hackings include, for example, those known in the art for makingcoated abrasive articles. Typically, the backing has two opposed majorsurfaces, although this is not a requirement. The thickness of thebacking generally ranges from about 0,02 to about 5 millimeters,desirably from about 0.05 to about 2.5 millimeters, and more desirablyfrom about 0.1 to about 1.0 millimeter, although thicknesses outside ofthese ranges may also be useful. Generally, the strength of the backingshould be sufficient to resist tearing or other damage during abradingprocesses. The thickness and smoothness of the backing should also besuitable to provide the desired thickness and smoothness of the coatedabrasive article; for example, depending on the intended application oruse of the coated abrasive article.

Exemplary backings include dense nonwoven fabrics (e.g., needletacked,meltspun, spunbonded, hydroentangled, or meltblown nonwoven fabrics),knitted fabrics, stitchbonded and/or woven fabrics; scrims; polymerfilms; treated versions thereof; and combinations of two or more ofthese materials.

Fabric backings can be made from any known fibers, whether natural,synthetic or a blend of natural and synthetic fibers. Examples of usefulfiber materials include fibers or yarns comprising polyester (e.g.,polyethylene terephthalate), polyamide hexamethylene adipamide,polycaprolactam), polypropylene, acrylic, cellulose acetate,polyvinylidene chloride-vinyl chloride copolymers, vinylchloride-acrylonitrile copolymers, graphite, polyimide, silk, cotton,linen, jute, hemp, or rayon. Useful fibers may be of virgin materials orof recycled or waste materials reclaimed from garment cuttings, carpetmanufacturing, fiber manufacturing, or textile processing, for example.Useful fibers may be homogenous or a composite such as a bicomponentfiber (for example, a co-spun sheath-core fiber). The fibers may betensilized and crimped, but may also be continuous filaments such asthose formed by an extrusion process.

The backing may have any suitable basis weight; typically, in a range offrom 100 to 1250 grams per square meter (gsm), more typically 450 to 600gsm, and even more typically 450 to 575 gsm. In many embodiments (e.g.,abrasive belts and sheets), the backing typically has good flexibility;however, this is not a requirement (e.g., vulcanized fiber discs). Topromote adhesion of binder resins to the backing, one or more surfacesof the backing may be modified by known methods including coronadischarge, ultraviolet light exposure, electron beam exposure, flamedischarge, and/or scuffing.

The make layer is formed by at least partially curing, a make layerprecursor comprising a thermosetting/curable composition. Examples ofsuitable thermosetting/curable resins that may be useful for the makelayer precursor include, for example, free-radically polymerizablemonomers and/or oligomers, epoxy resins, acrylic resins, urethaneresins, phenolic resins, urea-formaldehyde resins, melamine-formaldehyderesins, aminoplast resins, cyanate resins, and combinations thereof.Useful binder precursors include thermally curable resins and radiationcurable resins, which may he cured, for example, thermally and/or byexposure to radiation. Additional details concerning make layerprecursors may be found in U.S. Pat. No. 4,588,419 (Caul et al.), U.S.Pat. No. 4,751,138 (Tumey et al.), and U.S. Pat. No. 5,436,063 (Follettet al.).

The make layer precursor and the make layer may be modified by variousadditives (e.g., fibers, lubricants, wetting agents, surfactants,pigments, dyes, antistatic agents (e.g., carbon black, vanadium oxide,and/or graphite.), coupling agents (e.g., silanes, titanates,zircoaluminates, etc.), plasticizers, suspending agents). In someembodiments, the make layer precursor comprises a resole phenolic resinand an organic polymeric rheology modifier of a type suitable for use ina size layer and/or supersize layer precursor, and which may aid inpreserving the initial placement and orientation of the abrasiveparticles during manufacture.

At least one of the size layer precursor and/or the optional supersizelayer precursor comprises a resole phenolic resin and an organicpolymeric rheology modifier.

The organic polymeric rheology modifier comprises analkali-swellable/soluble polymer. On a solids basis, the amount of theresole phenolic resin comprises from 75 to 99.99 weight percent of thecombined weight of the resole phenolic resin and the organic polymericrheology modifier.

In embodiments, wherein the optional supersize layer precursor ispresent and comprises resole phenolic resin and an organic polymericrheology modifier according to the present disclosure, the size layerprecursor may comprise a different thermosetting/curable composition.Examples of suitable thermosetting/curable resins that may be useful forthe size layer precursor include, for example, free-radicallypolymerizable monomers and/or oligomers, epoxy resins, acrylic resins,urethane resins, phenolic resins, urea-formaldehyde resins,melamine-formaldehyde resins, aminoplast resins, cyanate resins, andcombinations thereof. Useful binder precursors include thermally curableresins and radiation curable resins, which may be cured, for example,thermally and/or by exposure to radiation. Additional details concerningsize layer precursors may be found in U.S. Pat. No. 4,588,419 (Caul etal.), U.S. Pat. No. 4,751,138 (Tumey et al.), and U.S. Pat. No.5,436,063 (Follett et al.). The size layer precursor may also hemodified by various additives such as, for example, fibers, lubricants,wetting agents, surfactants, pigments, dyes, antistatic agents (e.g.,carbon black, vanadium oxide, and/or graphite), coupling agents (e.g.,silanes, titanates, zircoaluminates, etc.), plasticizers, and/orsuspending agents.

In embodiments, wherein the supersize layer precursor comprises resolephenolic resin and an organic polymeric rheology modifier, and asupersize layer is present, it may comprise components as described forthe size layer precursor, or components known in the art for use as asupersize layer, for example. Examples of useful supersize layerprecursor compositions include metal salts of fatty acids,urea-formaldehyde, novolac phenolic resins, epoxy resins, waxes, mineraloils, mid combinations thereof.

If present, the supersize layer typically has a basis weight of 5 to1100 grams per square meter (gsm), preferably 50 to 700 gsm, and morepreferably 250 to 600 gsm, although this is not a requirement.

The basis weight of the make layer, size layer, and optional supersizelayer typically depend at least in part on the abrasive particle sizegrade and the particular type of abrasive article.

Phenolic resins are generally formed by condensation of phenol andformaldehyde, and are usually categorized as resole or novolac phenolicresins. Novolac phenolic resins are acid-catalyzed and have a molarratio of formaldehyde to phenol of less than 1:1. Resole (also resol)phenolic resins can be catalyzed by alkaline catalysts, and the molarratio of formaldehyde to phenol is greater than or equal to one,typically between 1,0 and 3.0, thus presenting pendant methylol groups.Alkaline catalysts suitable for catalyzing the reaction between aldehydeand phenolic components of resole phenolic resins include sodiumhydroxide, barium hydroxide, potassium hydroxide, calcium hydroxide,organic amines, and sodium carbonate, all as solutions of the catalystdissolved in water,

Resole phenolic resins are typically coated as a solution with waterand/or organic solvent (e.g., alcohol). ‘Typically, the solutionincludes about 70 percent to about 85 percent solids by weight, althoughother concentrations may be used. If the solids content is very low,then more energy is required to remove the water and/or solvent. If thesolids content is very high, then the viscosity of the resultingphenolic resin is too high which typically leads to processing problems.

Phenolic resins are well-known and readily available from commercialsources. Examples of commercially available resole phenolic resinsuseful in practice of the present disclosure include those marketed byDurez Corporation under the trade designation VARCUM (e.g., 29217,29306, 29318, 29338, 29353); those marketed by Ashland Chemical Co. ofBartow, Florida under the trade designation AEROFENE (e.g., AEROFENE295); and those marketed by Kangnam Chemical Company Ltd. of Seoul,South Korea under the trade designation PHENOLITE (e.g., PHENOLITETD-2207).

A general discussion of phenolic resins and their manufacture is givenin Kirk- Miner,

Encyclopedia of Chemical Technology, 4th Ed., John Wiley & Sons, 1996,New York, Vol. 18, pp. 603-644.

In addition to the resole phenolic resin, the curable compositioncontains an organic polymeric rheology modifier that comprises analkali-swellable/sohible polymer. The curable composition comprises aresole phenolic resin (typically diluted with water) and an organicpolymeric rheology modifier that comprises an alkali-swellable/solublepolymer. On a solids basis, wherein the amount of the resole phenolicresin comprises from 75 to 99.99 weight percent (preferably 82 to 99.99weight percent, and even more preferably 88 to 99.99 weight percent) ofthe combined weight of the resole phenolic resin and the organicpolymeric rheology modifier. Accordingly, the curable compositioncontains from 0.01 to 25 weight percent, preferably 0.01 to 18 weightpercent, and more preferably 0.01 to 12 weight percent of the organicpolymeric rheology modifier, based on the combined weight of the resolephenolic resin and the organic polymeric rheology modifier. Combinationsof more than one resole phenolic resin and/or more than one organicpolymeric rheology modifier may be used if desired.

Alkali-swellable/soluble polymers suitable for use as the organicpolymeric rheology modifier include, for example,Alkali-Swellable/soluble Emulsion (ASE) organic polymers,Hydrophobically-modified Alkali-Swellable/soluble Emulsion polymers(HASE), and Hydrophobically modified Ethoxylated URethane polymers(HEUR).

The organic polymeric rheology modifier may be chosen fromalkali-swellable/soluble acrylic emulsion polymers (ASE),Hydrophobically-modified alkali-swellable/soluble acrylic emulsionpolymers (HASE), and Hydrophobically-modified Ethoxylated URethane(HEUR) organic polymers, for example.

Alkali-Swellable/soluble Emulsion (ASE) rheology modifiers aredispersions of insoluble acrylic polymers in water have a highpercentage of acid groups distributed throughout their polymer chains.When these acid groups are neutralized, the salt that is formed ishydrated. Depending on the concentration of acid groups, the molecularweight and degree of crosslinking, the salt either swells in aqueoussolutions or becomes completely water-soluble.

As the concentration of neutralized polymer in an aqueous formulationincreases, the polymer chains swell, thereby causing the viscosity toincrease.

ASE polymers can be synthesized from acid and acrylate co-monomers, andare generally made through emulsion polymerization. Exemplarycommercially available ASE polymers include ACUSOL 810A, ACUSOL 830,ACUSOL 835, and ACUSOL 842 polymers.

Hydrophobically-modified Alkali-Swellabie/soluble Emulsion (HASE)polymers are commonly employed to modify’ the rheological properties ofaqueous emulsion systems. Under the influence of a base, organic orinorganic, the HASE particles gradually swell and expand to form athree-dimensional network by intermolecular hydrophobic aggregationbetween HASE, polymer chains and/or with components of the emulsion.This network, combined with the hydrodynamic exclusion volume created bythe expanded HASE chains, produces the desired thickening effect. Thisnetwork is sensitive to applied stress, breaks down under shear andrecovers when the stress is relieved.

HASE rheology modifiers can be prepared from the following monomers: (a)an ethylenically unsaturated carboxylic acid, (b) a nonionicethylenically unsaturated monomer, and (c) an ethylenically unsaturatedhydrophobic monomer. Representative HASE polymer systems include thoseshown in EP 226097 B1 (van Phung et al.), EP 705852 B1 (Doolan et al.),U.S. Pat. No. 4,384,096 (Sonnabend) and U.S. Pat. No. 5,874,495(Robinson).

Exemplary commercially available HASE polymers include those marketed byDow Chemical under the trade designations ACUSOL 801S, ACUSOL 8055,ACUSOL 820, and ACUSOL 823.

ASE and HASE rheology modifiers are pH-triggered thickeners. Whether theemulsion polymer in each is water-swellable or water-soluble typicallydepends on its molecular weight. Both forms are acceptable. Furtherdetails concerning synthesis of ASE and HASE polymers call be found, forexample, in U.S. Pat. No. 9,6:31E165 (Droege et al.).

Hydrophobically-modified Ethoxylated URethane (HEUR) polymers aregenerally synthesized from an alcohol, a diisocyanate and one or morepolyalkylene glycols. HEURs are water-soluble polymers containinghydrophobic groups, and are classified as associative thickeners becausethe hydrophobic groups associate with one another in water. UnlikeHASEs, HEURs are nonionic substances and are not dependent on alkali foractivation of the thickening mechanism They develop intra- orintermolecular links as their hydrophobic groups associate with otherhydrophobic ingredients in a given formulation. As a general rule, thestrength of the association depends on the number, size, and frequencyof the hydrophobic capping or blocking units. HEURs develop micelles aswould a normal surfactant. The micelles then link between the otheringredients by associating with their surfaces. This builds athree-dimensional network.

Exemplary commercially available HEUR polymers include those marketed byDow Chemical under the trade designations ACUSOL 880, ACUSOL 882,ACRYSOL RM-2020, and ACRYSOL RM-8W.

Further details concerning HEURs can be found, for example, in U.S. Pat.Appl. Publ. No.

2017/0198238 (Kensicher et al.) and 2017/0130072 (McCulloch et al.,) andU.S. Pat. No. 7,741,402 (Bobsein et al.) and 8,779,055 (Rabasco et al.).

The make layer, size layer, and optional supersize layer are formed byat least partially curing corresponding precursors (i.e., a make layerprecursor, a size layer precursor, a supersize layer precursor). ‘Themake layer, size layer, and optional supersize layer and theirprecursors new also contain additives such as fibers, Mbricants, wettingagents, surfactants, pigments, dyes, antistatic agents (e.g., carbonblack, vanadium oxide, and/or graphite), coupling agents (e.g., silanes,titanates, andior zircoaluminates), plasticizers, suspending agents, andthe like. The amounts of these optional additives are selected toprovide the preferred properties. The coupling agents can improveadhesion to the abrasive particles and/or filler. The curablecomposition may be thermally-cured, radiation-cured, or a combinationthereof.

The make layer, size layer, and optional supersize layer and theirprecursors may also contain filler materials, diluent abrasive particles(e.g., as described hereinbelow), or grinding aids, typically in theform of a particulate material. Typically, the particulate materials areinorganic materials. Examples of useful fillers for this disclosureinclude: metal carbonates (e.g., calcium carbonate (e.g., chalk,calcite, marl, travertine, marble and limestone), calcium magnesiumcarbonate, sodium carbonate, magnesium carbonate), silica (e.g., quartz,glass beads, glass bubbles and glass fibers) silicates (e.g., talc,clays, (montmorillonite) feldspar, mica, calcium silicate, calciummetasilicate, sodium aluminosilicate, sodium silicate) metal sulfates(e.g., calcium sulfate, barium sulfate, sodium sulfate, aluminum sodiumsulfate, aluminum sulfate), gypsum, vermiculite, wood flour, aluminumtrihydrate, carbon black, metal oxides (e.g., calcium oxide (lime),aluminum oxide, titanium dioxide), and metal sulfites (e.g., calciumsulfite). Heat energy is commonly applied to advance curing of thethermosetting/curable resins used in the make layer precursor/size layerprecursor, and optionally in the supersize layer precursor; however,other sources of energy (e.g., microwave radiation, infrared light,ultraviolet light, visible light, may also be used). The selection willgenerally be dictated by the particular resin system selected.

Useful abrasive particles may be the result of a crushing operation(e.g., crushed abrasive particles that have been sorted for shape andsize) or the result of a shaping operation (i.e., shaped abrasiveparticles) in which an abrasive precursor material is shaped (e.g.,molded), dried, and converted to ceramic material. Combinations ofabrasive particles resulting, from crushing with abrasive particlesresulting from a shaping operation may also be used. The abrasiveparticles may be in the form of, for example, individual particles,agglomerates, composite particles, and mixtures thereof.

The abrasive particles should have sufficient hardness and surfaceroughness to function as crushed abrasive particles in abradingprocesses. Preferably, the abrasive particles have a Mohs hardness of atleast 4, at least 5, at least 6, at least 7, or even at least 8.

Suitable abrasive particles include, for example, crushed abrasiveparticles comprising fused aluminum oxide, heat-treated aluminum oxide,white fused aluminum oxide, ceramic aluminum oxide materials such asthose commercially available as 3M CERAMIC ABRASIVE, GRAIN from 3M

Company, St. Paul, Minn., brown aluminum oxide, blue aluminum oxide,silicon carbide (including green silicon carbide), titanium diboride,boron carbide, tungsten carbide, garnet, titanium carbide, diamond,cubic boron nitride, garnet, fused alumina zirconia, iron oxide,chromia, zirconia, titania, tin oxide, quartz, feldspar, flint, emery,sol-gel-derived ceramic (e.g., alpha alumina), and combinations thereof.Examples of sol-gel-derived abrasive particles from which the abrasiveparticles can be isolated, and methods for their preparation can befound, in U.S. Pat. No. 4,314,827 (Leitheiser et al.); 4,623,364(Cot⁻winger et al.); 4,744,802 (Schwabel), 4,770,671 (Monroe et al.);and 4,881,951 (Monroe et al.). It is also contemplated that the abrasiveparticles could comprise abrasive agglomerates such, for example, asthose described in U.S. Pat. No. 4,652,275 (Bloecher et al.) or4,799,939 (Bloecher et al.). In some embodiments, the abrasive particlesmay be surface-treated with a coupling agent (e.g., an organosilanecoupling agent) or other physical treatment (e.g, iron oxide or titaniumoxide) to enhance adhesion of the crushed abrasive particles to thebinder. The abrasive particles may be treated before combining them withthe binder, or they may be surface treated in situ by including acoupling agent to the binder.

Preferably, the abrasive particles (and especially the abrasiveparticles) comprise ceramic abrasive particles such as, for example,sol-gel-derived polyctvstalline alpha alumina particles. Ceramicabrasive particles composed of crystallites of alpha alumina, magnesiumalumina spinel, and a rare earth hexagonal aluminate may be preparedusing sol-gel precursor alpha alumina particles according to methodsdescribed in, for example, U.S. Pat. No. 5,213,591 (Celikkaya et al.)and U.S. Publ. Pat. Apple. Nos. 2009/0165394 A1 (Culler et al.) and2009/0169816 A1 (Erickson et al.). Further details concerning methods ofmaking sol-gel-derived abrasive particles can be found in, for example,U.S. Pat. No. 4,314,827 (Leitheiser); U.S. Pat. No. 5,152,917 (Pieper etal); U.S. Pat. No. 5,435,816 (Spurgeon et al.); 5,672,097 (Hoopman etal.); 5,946,991 (Hoopman et al.); 5,975,987 (Hoopman et al.), and6,129,540 (Hoopman et al.); and in U.S. Publ. Pat, Apple. No.

2009/0165:394 Al (Culler et at).

In some preferred embodiments, useful abrasive particles (especially inthe case of the abrasive particles) may be shaped abrasive particles canbe found in U.S. Pat. No. 5,201,916 (Berg); 5,366,523 (Rowenhorst (Re35,570)); and 5,984,988 (Berg). U.S. Pat. No. 8,034,137 (Erickson etal.) describes alumina abrasive particles that have been formed in aspecific shape, then crashed to form shards that retain a portion oftheir original shape features. In some embodiments, the abrasiveparticles are precisely-shaped (i.e., the particles have shapes that areat least partially determined by the shapes of cavities in a productiontool used to make them. Details concerning such abrasive particles andmethods for their preparation can be found, for example, in U.S. Pat.No. 8,142,531 (Adefris et al.); 8,142,891 (Culler et al.); 8,142,532(Erickson et al.); 9,771,504 (Adefris); and in U.S. Pat. Appl. Publ.Nos. 2012/0227333 (Adefris et al.); 2013/0040537 (Schwabel et al.); and201 3/0 12 5477 (Adefris). One particularly useful precisely-shapedabrasive particle shape is that of a platelet having three-sidewalls,any of which may be straight or concave, and which may he vertical orsloping with respect to the platelet base; for example, as set forth inthe above cited references. An exemplaty such precisely-shaped abrasiveparticle 200 is shown in FIG. 2 .

Surface coatings on the abrasive particles may be used to improve theadhesion between the abrasive particles and a binder material, or to aidin electrostatic deposition of the abrasive particles. In oneembodiment, surface coatings as described in U.S. Pat. No. 5,352,254(Celikkaya) in an amount of 0.1 to 2 percent surface coating to abrasiveparticle weight may be used. Such surface coatings are described in U.S.Pat. No. 5,213,591 (Celikkaya et al.); 5,011,508 (Wild et al), 1,910,444(Nicholson), :3,041,156 (Rowse et al.); 5,009,675 (Kunz et al.);5,085,671 (Martin et al.); 4,997,461 (Markhoff-Matheny et al.); and5,042,991 (Kunz et al.). Additionally, the surface coating may preventshaped abrasive particles from capping. Capping is the term to describethe phenomenon where metal particles from the workpiece being abradedbecome welded to the tops of the abrasive particles. Surface coatings toperform the above functions are known to those of skill in the art.

In some embodiments, the abrasive particles may be selected to have alength and/or width in a.

range of from 0.1 micrometers to 3.5 millimeters (mm), more typically0.05 mm to 3.0 mm, and more typically 0.1 mm to 2.6 mm, although otherlengths and widths may also be used.

The abrasive particles may be selected to have a thickness in a range offrom 0.1 micrometer to 1.6 ram, more typically from 1 micrometer to 1.2mm, although other thicknesses may be used. In some embodiments,abrasive particles may have an aspect ratio (length to thickness) of atleast 2, 3, 4, 5, 6, or more.

Abrasive particles may be independently sized according to an abrasivesindustry’ recognized specified nominal grade. Exemplary abrasiveindustry recognized grading standards include those promulgated by ANSI(American National Standards Institute), FEPA (Federation of EuropeanProducers of Abrasives), and JIS (Japanese Industrial Standard). Suchindustry accepted grading standards include, for example: ANSI 4, ANSI6, ANSI 8, ANSI 16, ANSI 24, ANSI 30, ANSI 36, ANSI 40, ANSI 50, ANSI60, ANSI 80, ANSI 100, ANSI 120, ANSI 150, ANSI 180, ANSI 220, ANSI 240,ANSI 280, ANSI 320,

ANSI 360, ANSI 400, and. ANSI 600; FEPA P8, FEPA P12, FEPA P16, FEPAP24, FEPA P30, FEPA P36, FEPA P40, FEPA P50, FEPA P60, FEPA P80, FEPAP100, FEPA P120, FEPA P150, FEPA P180, FEPA P220, FEPA P320, FEPA P400,FEPA P500, FEPA P600, FEPA P800, FEPA P1000, FEPA P1200; FEPA F8, FEPAF12, FEPA F16, and FEPA F24;.and JIS 8, JIS 12, HS 16, JIS 24, JIS 36,ES 46, JIS 54, JIS 60, JIS 80, JIS 100, JIS 150, JIS 180, JIS 220, HS240, JIS 280, HS 320, JIS 360, JIS 400, JIS 600, JIS 800, JIS 1000, JIS1500, HS 2500, JIS 4000, ES 6000, JIS 8000, and JIS 10,000. Moretypically, the crushed aluminum oxide particles and the non-seededsol-gel derived alumina-based abrasive particles are independently sizedto ANSI 60 and 80, or FEPA F36, F46, F54 and F60 or FEPA P60 and P80grading standards.

Alternatively, the abrasive particles can be graded to a nominalscreened grade using U.S.A. Standard Test Sieves conforming to ASTM E-11“Standard Specification for Wire Cloth and Sieves for Testing Purposes”,ASTM E-1 I prescribes the requirements for the design and constructionof testing sieves using a medium of woven wire cloth mounted in a framefor the classification of materials according to a designated particlesize. A typical designation may be represented as -18+20 meaning thatthe shaped 2.5 abrasive particles pass through a test sieve meeting ASTME-11 specification for the number 18 sieve and are retained on a testsieve meeting ASTM E-11 specification for the number 20 sieve. In oneembodiment, the shaped abrasive particles have a particle size such thatmost of the particles pass through an 18 mesh test sieve and can beretained on a 20, 25, 30, 35, 40, 45, or 50 mesh test sieve. In variousembodiments, the shaped abrasive particles can have a nominal screenedgrade comprising: -18+20, -20+25, -25+30, -30+35, -35+40, -40+45,-45+50, -50+60, -60+70, -70+80, -80+100, -100+120, -120+140, -140+170,-170+200, -200+230, -230+270, -270+325, -325+400, -400+450, -450+500, or-500+635. Alternatively, a custom mesh size could be used such as-90+100.

A grinding aid is a material that has a significant effect on thechemical and physical processes of abrading, which results in improvedperformance. Grinding aids encompass a wide variety of differentmaterials and can be inorganic or organic based. Examples of chemicalgroups of grinding aids include waxes, organic halide compounds, halidesalts and metals and their alloys. The organic halide compounds willtypically break down during abrading and release a halogen acid or agaseous halide compound.

Examples of such materials include chlorinated waxes liketetrachloronaphthalene, pentachloronaphthalene, and polyvinyl chloride.Examples of halide salts include sodium chloride, potassium cryolite,sodium cryolite, ammonium cryolite, potassium tetrafluoroborate, sodiumtetrafluoroborate, silicon fluorides, potassium chloride, and magnesiumchloride. Examples of metals include, tin, lead, bismuth, cobalt,antimony, cadmium, iron, and titanium.

Other miscellaneous grinding aids include sulfur, organic sulfurcompounds, graphite, and metallic sulfides. A combination of differentgrinding aids may be used, and in some instances, this may produce asynergistic effect.

Grinding aids can be particularly useful in coated abrasives. In coatedabrasive articles, grinding aid is typically used in a supersize layer,which is applied over the surface of the size layer. Sometimes, however,the grinding aid is added to the size layer. Typically, the amount ofgrinding aid incorporated into coated abrasive articles are about 50-800grams per square meter (g/m²), preferably about 80-475 g/m², however,this is not a requirement.

Further details regarding coated abrasive articles and methods of theirmanufacture call be found, for example, in U.S. Pat: Nos, 4,734,104(Broberg); 4,7:37,163 (Larkey); 5,20:3,884 (Buchanan et al.); 5, 152,917(Pieper et al,); 5,378,251 (Culler et al.); 5,436,063 (Follett et al.);5,496,:386 (Broberg et al,); 5,609,706 (Benedict et al.); 5, 520,711(Helmin); U.S. Pat. No. 5,961,674 (Gagliardi et al.), and 5,975,988(Christianson).

Coated abrasive articles according to the present disclosure are useful,for example, for abrading a workpiece. Such a method may comprisefrictionally contacting an abrasive article according to the presentdisclosure with a surface of the workpiece, and moving at least one ofthe coated abrasive article and the surface of the workpiece relative tothe other to abrade at least a portion of the surface of the workpiece.Methods for abrading with coated abrasive articles according to thepresent disclosure include, for example, snagging (i.e., high-pressurehigh stock removal) to polishing (e.g., polishing medical implants withcoated abrasive belts), wherein the latter is typically done with finergrades (e.g., ANSI 220 and finer) of abrasive particles. The size of theabrasive particles used fora particular abrading application will beapparent to those skilled in the art.

Abrading may be carried out dry or wet. For wet abrading, the liquid maybe introduced supplied in the form of a light mist to complete flood:Examples of commonly used liquids include water, water-soluble oil,organic lubricant, and emulsions: The liquid may serve to reduce theheat associated with abrading and/or act as a lubricant. The liquid maycontain minor amounts of additives such as bactericide, antifoamingagents, and the like.

Examples of workpieces include aluminum metal, carbon steels, mildsteels (e.g., 1018 mild steel and 1045 mild steel), tool steels,stainless steel, hardened steel, titanium, glass, ceramics, wood,wood-like materials (e.g., plywood and particle hoard), paint, paintedsurfaces, and organic coated surfaces. The applied force during abradingtypically ranges from about 1 to about 100 kilograms (kg), althoughother pressures can also be used.

SELECT EMBODIMENTS OF THE PRESENT DISCLOSURE

In a first embodiment, the present disclosure provides a method ofmaking a coated abrasive article comprising:

providing a backing having first and second opposed major surfaces,wherein a make layer is disposed on at least a portion of the firstmajor surface and bonds abrasive particles to the backing;

coating a size layer precursor over at least a portion of the make layerand the abrasive particles, wherein the size layer precursor comprises aresole phenolic resin and an organic polymeric rheology modifier,wherein the organic polymeric rheology modifier comprises analkali-swellable/soluble polymer, and, on a solids basis, and whereinthe amount of the resole phenolic resin comprises from 75 to 99.99weight percent of the combined weight of the resole phenolic resin andthe organic polymeric rheology modifier; and

at least partially curing the size layer precursor to provide a sizelayer; and

optionally coating an optional supersize layer precursor over at least aportion of the size layer and at least partially curing the optionalsupersize layer precursor to provide an optional supersize layer,

wherein at least one of the size layer precursor or the optionalsupersize layer precursor comprises a resole phenolic resin and anorganic polymeric rheology modifier, wherein the organic polymericrheology modifier comprises an alkali-swellable/soluble polymer, and, ona solids basis, and wherein the amount of the resole phenolic resincomprises from 75 to 99.99 weight percent of the combined weight of theresole phenolic resin and the organic polymeric rheology modifier.

In a second embodiment, the present disclosure provides a methodaccording to the first embodiment, wherein at least one of said at leastpartially curing the size layer precursor or said at least partiallycuring the supersize layer precursor occurs in a festoon oven.

In a third embodiment, the present disclosure provides a methodaccording to the first or second embodiment, wherein at least one of thesize layer precursor or the optional supersize layer precursor has abasis weight of 5 to 1100 grams per square meter.

In a fourth embodiment, the present disclosure provides a methodaccording to any of the first to third embodiments, wherein the organicpolymeric rheology modifier is selected from the group consisting ofalkali-swellable/soluble acrylic polymers, hydrophobically-modifiedalkali-swellable/soluble acrylic polymers, hydrophobically-modifiedethoxylated urethane polymers, and combinations thereof.

In a fifth embodiment, the present disclosure provides a methodaccording to any of the first to fourth embodiments, wherein, on asolids basis, the amount of the resole phenolic resin comprises from 85to 99.99 weight percent of the combined weight of the resole phenolicresin and the organic polymeric rheology modifier.

In a sixth embodiment, the present disclosure provides a methodaccording to any of the first to fifth embodiments, wherein the abrasiveparticles comprise shaped abrasive particles.

In a seventh embodiment, the present disclosure provides a methodaccording to the sixth embodiment, wherein the shaped abrasive particlescomprise precisely-shaped abrasive particles.

In an eighth embodiment, the present disclosure provides a methodaccording to the sixth embodiment, wherein the shaped abrasive particlescomprise precisely-shaped three-sided platelets. In a ninth embodiment,the present disclosure provides a coated abrasive article comprising:

a hacking having first and second opposed major surfaces, a make layerdisposed on at least a portion of the first major surface and bondingabrasive particles to the backing;

a size layer overlaid on at least a portion of the make layer and theabrasive particles; and

an optional supersize layer,

wherein at least one of the size layer or the optional supersize layercomprises an at least partially cured. resole phenolic resin and anorganic polymeric rheology modifier, and wherein the amount of the atleast partially cured resole phenolic resin comprises from 75 to 99.99weight percent of the combined weight of the at least partially curedresole phenolic resin and the organic polymeric rheology modifier.

In a tenth embodiment, the present disclosure provides a coated abrasivearticle according to the ninth embodiment, wherein the organic polymericrheology modifier is selected from the group consisting ofalkali-swellableIsoluble acrylic polymers, hydrophobically-modifiedalkali-swellablesoltible acrylic polymers, hydrophobically-modifiedethoxylated urethane polymers, and combinations thereof.

In an eleventh embodiment, the present disclosure provides a coatedabrasive article according to the ninth or tenth embodiment, wherein theamount of the at least partially cured resole phenolic resin comprisesfrom 85 to 99.99 weight percent of the combined weight of the at leastpartially cured resole phenolic resin and the organic polymeric rheologymodifier.

In a twelfth embodiment, the present disclosure provides a coatedabrasive article according to any of the ninth to eleventh embodiments,wherein the abrasive particles comprise shaped abrasive particles.

In a thirteenth embodiment, the present disclosure provides a coatedabrasive article according to the twelfth embodiment, wherein the shapedabrasive particles comprise precisely-shaped abrasive particles.

In a fourteenth embodiment, the present disclosure provides a coatedabrasive article according to the twelfth embodiment, wherein die shapedabrasive particles comprise precisely-shaped three-sided platelets.

Objects and advantages of this disclosure are further illustrated by thefollowing non-limiting examples, but the particular materials andamounts thereof recited in these examples, as well as other conditionsand details, should not be construed to unduly limit this disclosure.

Examples

Unless otherwise noted, all parts, percentages, ratios, etc. in theExamples and the rest of the specification are by weight.

TABLE OF MATERIALS USED IN THE EXAMPLES ABBREVIATION DESCRIPTION ANDSOURCE PF Resole resin (75 wt. % in water), a phenol:formaldehyde (molarratio of 1:1.5to 1:2.1) condensate catalyzed by 1 to 5% metal hydroxide.Obtained from Georgia Pacific, Atlanta, Georgia. ADD 1 A hydrophobicallymodified alkali swellable acrylic polymer emulsion (HASE) obtained asACUSOL 820 from The Dow Chemical Company, Midland, Michigan. Obtained asan aqueous emulsion with 29.77% solids content. ADD 2 An alkaliswellable acrylic polymer emulsion (ASE) obtained as ACUSOL 835 from TheDow Chemical Company. Obtained as an aqueous emulsion with 28.75% solidscontent. ADD 3 An alkali swellable acrylic polymer emulsion (ASE)obtained as RHEOVIS AS 1130 from BASF, Florham Park, New Jersey.Obtained as an aqueous emulsion with 31.3% solids content. ADD 4Hydrophilic amorphous fumed silica obtained as CAB-O-SIL M-5 from CabotCorporation, Alpharetta, Georgia. ADD 5 Hydrophilic amorphous fumedsilica dispersed in water at 18% solids obtained under the tradedesignation Cab-O-Sperse from Cabot Corporation. FIL1 Calcium silicateobtained under the trade designation M400 WOLLASTOCOAT. Obtained fromNYCO, Willsboro, New York. FIL2 Cryolite obtained under the tradedesignation CRYOLITE RTN-C. Obtained from FREEBEE A'S, Ullerslev,Denmark. FIL3 Potassium tetrafluoroborate obtained from AWSM industries,Paramus, NJ, under trade designation potassium fluoroborate. FIL4Calcium silicate obtained as 400 WOLLASTOCOAT 10014 from NYCO,Willsboro, New York RIO Red iron oxide pigment obtained under the tradedesignation KROMA RO-3097. from Elementis, East Saint Louis, Illinois.Surf 1 Surfactant obtained under trade designation Aerosol OT-NV, fromCytec-Solvay Group, Stamford, Connecticut. Surf 2 Surfactant obtainedunder trade designation Foamstar ST 2425 (formerly ST 125), from BASFCorporation. SAP1 Shaped abrasive particles were prepared according tothe disclosure of U.S. Pat. No. 8,142,531 (Adefris et al). The shapedabrasive particles were prepared by molding alumina sol gel inequilateral triangle-shaped polypropylene mold cavities. After dryingand firing, the resulting shaped abrasive particles, which were shapedas truncated triangular pyramids, were about 1.4 mm (side length) × 0.35mm (thickness), with a draft angle approximately 98 degrees.

Preparation of Size and Supersize Examples and Comparative Examples

Examples and comparative examples were prepared by massing allcomponents into 3-Liter or 70-mm diameter polypropylene straight-walledjars according to the amounts indicated in Tables 1-4. Jars orcontainers were mixed with an overhead stirrer. If the mixture was notused for testing immediately it was stored in a refrigerator at 10° C.until use.

TABLE 1 SIZE RESIN COMPARATIVE EXAMPLE PRECURSOR COMPONENT CE-A CE-B PF(amount in grams) 1263.2 1062.4 FIL1 (amount in grams) 664.1 1643.4 FIL2 (amount in grams) 664.1 0 RIO (amount in grams) 46.4 49.8 Water(amount in grams) 362.2 244.4 % Solids 77.4 83

TABLE 2 SIZE RESIN COMPARATIVE EXAMPLE PRECURSOR COMPONENT CE-C CE-DCE-E CE-F CE-G CE-A (amount in grams) 199.50 199.00 198.50 198.00 99.50ADD 4 (amount in grams) 0.50 1.00 1.50 2.00 ADD 5 (amount in grams) 3.00% Total Solids 77.46 77.51 77.57 77.63 75.66

TABLE 3 SIZE RESIN COMPARATIVE EXAMPLE PRECURSOR COMPONENT CE-H CE-ICE-B (amount in grams) 199.00 99.50 ADD 4 (amount in grams) 1.00 ADD 5(amount in grams) 3.00 % Total Solids 83.09 81.10

TABLE 4 SIZE LAYER PRECURSOR EXAMPLES EX-1 THROUGH EX-13 COMPONENT EX-1EX-2 EX-3 EX-4 EX-5 EX-6 EX-7 EX-8 EX-9 EX-10 EX-11 EX-12 EX-13 CE-A(amount 99.25 99.75 99.75 99.75 99.75 99.75 99.75 99.75 99.25 99.7599.75 99.75 99.75 in grams) ADD 1 0.20 0.10 0.05 (amount in grams) ADD 20.8 g 0.41 0.20 0.10 0.05 (amount in grams) ADD 3 0.80 0.41 0.20 0.100.05 (amount in grams) % Total Solids 77.01 77.20 77.30 77.35 77.3877.30 77.35 77.38 77.03 77.21 77.31 77.35 77.38

TABLE 5 SIZE LAYER PRECURSOR EXAMPLES EX-14 TO EX-16 COMPONENT EX-14EX-15 EX-16 EX-17 EX-18 EX-19 EX-20 EX-21 EX-22 EX-23 EX-24 EX-25 EX-26CE-B 99.25 99.75 99.75 99.75 99.75 99.75 99.75 99.75 99.25 99.75 99.7599.75 99.75 (amount in grams) ADD 1 0.20 0.10 0.05 (amount in grams) ADD2 0.80 0.41 0.20 0.10 0.05 (amount in grams) ADD 3 0.80 0.41 0.20 0.100.05 (amount in grams) % Total Solids 82.57 82.78 82.89 82.95 82.9782.89 82.95 82.97 82.59 82.79 82.90 82.95 82.97

TABLE 6 SIZE LAYER EXAMPLES PRECURSOR COMPONENT EX-27 EX-28 CE-A (amountin grams) 198.00 CE-B (amount in grams) 198.00 ADD 2 (amount in grams)3.40 3.40 % Total Solids 76.58 82.08

TABLE 7 SUPERSIZE LAYER PRECURSOR COMPONENT COMPARATIVE EXAMPLE CE-J PF(amount in grams) 149 FIL3 (amount in grams) 433 SURF 1 (amount ingrams) 8.63 SURF 2 (amount in grams) 2.75 Water (amount in grams) 160 %Total Solids 73.82

TABLE 8 SUPERSIZE LAYER COMPARATIVE EXAMPLE PRECURSOR COMPONENT CE-KCE-L CE-J (amount in grams) 99.60 99.75 ADD 4 (amount in grams) 0.400.25 % Total Solids 73.92 73.89

TABLE 9 SUPERSIZE LAYER EXAMPLE PRECURSOR COMPONENT EX-29 EX-30 CE-J(amount in grams) 98.00 99.00 ADD 2 (amount in grams) 2.00 1.00 % TotalSolids 72.92 73.37

Inclined Plane Flow Test for Size and Supersize Layer Precursor Examplesand Comparative Examples

The incline flow rate test involved placing 0.1 gram drop of resin atspecified temperature onto horizontal positioned glass slide and thenquickly tilting glass slide on incline device set at 48.7′ angle fromhorizontal for one minute. The distance the resin travels in one minuteis measured in millimeters (mm). The smaller the distance the lesslikely size or supersize resin will have excessive flow and cause bottomloop puddling in the festoon curing ovens. The incline data for SizeResin examples and comparative examples are reported in Tables 10 and11. Supersize Resin examples and comparative examples are shown in Table12.

TABLE 10 INCLINE PLANE FLOW TEST DATA FOR SIZE LAYER PRECURSORS BASED ONCOMPARATIVE EXAMPLE CE-A EXAMPLE/ INCLINE TEST COMPARATIVE % SOLIDADDITIVE/ AT 41° C. - DISTANCE EXAMPLE % TOTAL SOLIDS TRAVELED (MM) CE-A0 44 CE-C 0.32 46 CE-D 0.65 28 CE-E 0.97 11 CE-F 1.29 10 CE-G 0.7 36EX-1 0.3 0 EX-2 0.15 0 EX-3 0.07 5 EX-4 0.04 5 EX-5 0.02 0 EX-6 0.08 4EX-7 0.04 0 EX-8 0.02 5 EX-9 0.32 0 EX-10 0.17 0 EX-11 0.08 4 EX-12 0.047 EX-13 0.02 3

TABLE 11 INCLINE PLANE FLOW TEST DATA FOR SIZE LAYER PRECURSORS BASED ONCOMPARATIVE EXAMPLE CE-B EXAMPLE/ INCLINE TEST COMPARATIVE % SOLIDADDITIVE/ AT 41° C. - DISTANCE EXAMPLE % TOTAL SOLIDS TRAVELED (MM) CE-B0 44 CE-M 0.6 28 CE-P 0.65 35 EX-14 0.28 15 EX-15 0.14 0 EX-16 0.07 0EX-17 0.03 0 EX-18 0.02 6 EX-19 0.07 0 EX-20 0.04 0 EX-21 0.02 0 EX-220.3 6 EX-23 0.16 7 EX-24 0.08 0 EX-25 0.04 4 EX-26 0.02 17

TABLE 12 INCLINE PLANE FLOW TEST DATA FOR SUPERSIZE LAYER PRECURSORSBASED ON COMPARATIVE EXAMPLE CE-J EXAMPLE/ INCLINE TEST AT COMPARATIVE %SOLID ADDITIVE/ ROOM TEMPERATURE - DISTANCE EXAMPLE % TOTAL SOLIDSTRAVELED (MM) CE-J 0 34 CE-K 0.54 17 CE-L 0.34 16 EX-29 0.79 6 EX-300.39 8

Viscosity Measurement Test Method

The flow characteristics of the phenolic copolymer mixtures werecharacterized by continuous flow rheometry using a TA InstrumentsDiscovery Hybrid. Rheometer 3 (TA Instruments. New Castle, Del.)equipped with a stainless steel concentric cylinder geometry utilizing aconical end rotor with a 28.01 mm diameter and 41.96 mm height, cup witha 30.35 mm diameter, and a TA instmments MIR & AR-Series Smart SwapConcentric Cylinder Peltier jacket for temperature control. Samplesapproximately 24 milliliters in volume were loaded onto the geometry cupvia polypropylene syringe and the rotor was brought to a gap height5.919 mm. An aluminum collar was fitted on the top of the cup tominimize water evaporation form the sample, while allowing free rotationof the rotor. Individual samples were thermally equilibrated in theinstrument for 300 seconds before testing. The stress dependent flowbehavior of the mixtures was investigated at 20, 40, and 60° C. using alogarithmic ramp over 180 seconds from 0.001-3000 pascals (Pa) appliedstress selecting 10 individual rates per decade. Table 13, below,reports the viscosity measured at 0.01s⁻and 100 s⁻¹ for all samplestested.

TABLE 13 EXAMPLE/ COMPARATIVE TEMPERATURE, VISCOSITY, Pa · s EXAMPLE °C. 10⁻² s⁻¹ 10² s⁻¹ CE-B 20 27.84 1.307 CE-A 20 158.00 0.600 EX 28 20506.30 11.780 40 838.60 5.707 60 1550.00 3.568 EX 27 20 40.39 2.554 4021.17 1.106 60 52.34 0.479

Preparation of Coated Abrasive Size and Supersize Resin Examples andComparative Examples Make Layer Precursor

A make layer precursor was prepared charging a 17-liter pail with 7812grams of PF, 6823 grams of FIL4 and 364 grams of water. The resin wasmixed with an overhead stirrer for 30 minutes at room temperature.

Size Layer Precursor - Comparative Example CE-ill

Coated abrasive examples and comparative examples were prepared by rollcoating make resin (described above) onto a continuous 30.48 cm widepolyester backing (described in Example 12 of U.S. Pat. No. 6,843,815Thurber et al.) at a coating weight of 210 grams per square meter (gsm)followed by electrostatically coating mineral SARI at a weight of 605gsm. The coated material was cured at 90° C. for 90 minutes and at 102°C. for 60 minutes. The resultant material was then roll coated with sizeresin Comparative Example CE-A at a size weight of 567 gsm. The materialwas final cured at 90″C for 60 minutes and at 102° C. for 12 hours.

Size Layer Precursor - Example EX-3I

Coated abrasive examples and comparative examples were prepared by rollcoating make resin (described above) onto a continuous 30.48 cm widepolyester backing (described in Example 12 of-U.S. Pat. No. 6,843,815Thurber et al.) at a coating weight of 210 gsm followed byelectrostatically coating mineral SAP I. at a weight of 605 gsm. Thecoated material was cured at 90° C. for 90 minutes and at 102° C. for 60minutes. The resultant material was then roll coated with size resinExample EX-27 at a size weight of 567 gsm. The material was final curedat 90° C. for 60 minutes and at 102° C. for 12 hours.

The coated abrasive Comparative Example CE-M showed typical bottom looppuddling while Example EX-31 had no observed puddling.

Supersize Layer Precursor - Comparative Example CE-N

Coated abrasive examples and comparative examples were prepared by rollcoating make resin (described above) onto a continuous 30.48 cm widepolyester backing (described in Example 12 of U.S. Pat. No. 6,843,815Thurber et al.) at a coating weight of 210 gsm followed byelectrostatically coating mineral SAP1 at a weight of 605 gsm. Thecoated material was cured at 90° C. for 90 minutes and at 102° C. for 60minutes. The resultant material was then roll coated with size resinComparative Example CE-A at a size weight of 567 gsm. The material wascured at 90° C. for 1 hour and at 102° C. for 1 hour. The resultantmaterial was then coated with supersize resin Comparative Example CE-Jat coating weight of 462 gsm using a 30448 cm paint roller. The coatedabrasive was final cured at 90° C. for 60 minutes and at 102° C. for 12hours.

Supersize Layer Precursor - Example EX-32

Coated abrasive examples and comparative examples were prepared by rollcoating make resin (described above) onto a continuous 30.48 cm widepolyester backing (described in Example 12 of U.S. Pat. No. 6,843,815Thurber et al.) ata coating weight of 210 gsln followed byelectrostatically coating mineral SAP1 at a weight of 605 gsm. Thecoated material was cured at 90° C. for 90 minutes and at 102° C. for 60minutes. The resultant material was then roll coated with size resinComparative Example CE-A at a size weight of 567 gsm. The material wascured at 90° C. for 1 hour and at 102° C. for 1 hour. The resultantmaterial was then coated with supersizc resin Example EX-29 at coatingweight of 462 gsm using a 30,48 cm paint roller. The coated abrasive wasfinal cured at 90° C. for 60 minutes and at 102° C. for 12 hours,

All cited references, patents, and patent applications in thisapplication that are incorporated by reference, are incorporated in aconsistent manner. In the event of inconsistencies or contradictionsbetween portions of the incorporated references and this application,the information in this application shall control. The precedingdescription, given in order to enable one of ordinary skill in the artto practice the claimed disclosure, is not to be consulted as limitingthe scope of the disclosure, which is defined by the claims and allequivalents thereto.

1. A method of making a coated abrasive article comprising: providing abacking having first and second opposed major surfaces, wherein a makelayer is disposed on at least a portion of the first major surface andbonds abrasive particles to the backing; coating a size layer precursorover at least a portion of the make layer and the abrasive particles,wherein the size layer precursor comprises a resole phenolic resin andan organic polymeric rheology modifier, wherein the organic polymericrheology modifier comprises an alkali-swellable/soluble polymer, and, ona solids basis, and wherein the amount of the resole phenolic resincomprises from 75 to 99.99 weight percent of the combined weight of theresole phenolic resin and the organic polymeric rheology modifier; andat least partially curing the size layer precursor to provide a sizelayer; wherein the size layer precursor comprises a resole phenolicresin and an organic polymeric rheology modifier, wherein the organicpolymeric rheology modifier comprises an alkali-swellable/solublepolymer, and, on a solids basis, and wherein the amount of the resolephenolic resin comprises from 75 to 99.99 weight percent of the combinedweight of the resole phenolic resin and the organic polymeric rheologymodifier.
 2. The method of claim 1, wherein at least one of said atleast partially curing the size layer precursor or said at leastpartially curing the supersize layer precursor occurs in a festoon oven.3. The method of claim 1, wherein at least one of the size layerprecursor or the optional supersize layer precursor has a basis weightof 5 to 1100 grams per square meter.
 4. (canceled)
 5. The method ofclaim 1, wherein, on a solids basis, the amount of the resole phenolicresin comprises from 85 to 99.99 weight percent of the combined weightof the resole phenolic resin and the organic polymeric rheologymodifier.
 6. The method of claim 1, wherein the abrasive particlescomprise shaped abrasive particles.
 7. The method of claim 6, whereinthe shaped abrasive particles comprise precisely-shaped abrasiveparticles.
 8. The method of claim 6, wherein the shaped abrasiveparticles comprise precisely-shaped three-sided platelets.
 9. A coatedabrasive article comprising: a backing having first and second opposedmajor surfaces, a make layer disposed on at least a portion of the firstmajor surface and bonding abrasive particles to the backing; a sizelayer overlaid on at least a portion of the make layer and the abrasiveparticles; and an optional supersize layer, wherein at least one of thesize layer or the optional supersize layer comprises an at leastpartially cured resole phenolic resin and an organic polymeric rheologymodifier, wherein the organic polymeric rheology modifier comprises analkali-swellable/soluble polymer, and wherein the amount of the at leastpartially cured resole phenolic resin comprises from 75 to 99.99 weightpercent of the combined weight of the at least partially cured resolephenolic resin and the organic polymeric rheology modifier. 10.(canceled)
 11. The coated abrasive article of claim 9, wherein theamount of the at least partially cured resole phenolic resin comprisesfrom 85 to 99.99 weight percent of the combined weight of the at leastpartially cured resole phenolic resin and the organic polymeric rheologymodifier.
 12. The coated abrasive article of claim 9, wherein theabrasive particles comprise shaped abrasive particles.
 13. The coatedabrasive article of claim 12, wherein the shaped abrasive particlescomprise precisely-shaped abrasive particles.
 14. The coated abrasivearticle of claim 12, wherein the shaped abrasive particles compriseprecisely-shaped three-sided platelets.